1. Field of the Invention
This invention relates to an improved tamper evident end cap assembly for a drug loaded syringe to seal it and to cap it protectively prior to injecting a patient with the drug; and, also, it relates to a package and the end cap assembly, as a combination, wherein the assembly is encapsulated within the package to be maintained in it in a sterile condition prior to capping a drug loaded syringe with it, and; further, it relates to a drug loaded syringe capped with the tamper evident end cap assembly ready to be opened to inject a patient with the drug or to return the drug load, if not used by the patient, to be down loaded at a station and recycled. The invention also relates to a process of manufacturing the end cap assembly and of using it by installing it on a mating syringe.
2. Description of the Related Art
This invention is disclosed in three forms:
a first form, which is a combination, composed of a drug loaded syringe having a nozzle with a discharge port or luer opening and a tamper evident end cap assembly according to the invention installed on the nozzle sealing and closing the luer opening and which cannot be removed to gain access to the drug load without creating palpable evidence of tampering;
a second form, which is another combination composed, of a) at least one tamper evident end cap assembly which has a structure according to the invention, and b) a sterile shipping and storage package encapsulating it, the end cap assembly including its end cap assembly luer lock syringe cap captivated within the end cap assembly is adapted to be removed from the package and installed on the nozzle of a mated standard syringe in a position from which it cannot be removed without creating evidence of the removal, and
a third form which is an improved combination, composed of a) a tamper evident end cap assembly which includes b) a luer lock syringe cap coaxially captivated yet rotatable on its axis within the assembly, the assembly being for mounting of it over the discharge port or luer opening of a dose loaded standard and mated syringe, the end cap assembly being improved with respect to known devices by structure set forth fully in this disclosure which, among other elements, includes a) a first one way drive means component on the syringe cap, b) a floor portion in the assembly to maintain the cap within the assembly which floor portion also has a axial one way drive means component, which mates with the first component to comprise a one way drive means to move the syringe cap axially in one direction only to tighten it on a syringe nozzle, and is disengaged and inefficient upon rotation in the other direction of rotation and c) a centering means on the floor portion to guide the syringe cap of the end cap assembly into coaxial engaged relation with other end cap assembly parts.
The invention is also of a process of manufacture of the foregoing structure and of the use of it.
Throughout this specification, the phrase xe2x80x9cstandard syringexe2x80x9d is used. This phrase is intended to refer to a plurality of xe2x80x9ccarbon copyxe2x80x9d syringes, usually made by a single manufacturer. A xe2x80x9ccarbon copyxe2x80x9d syringe is one of a group of syringes of the same type, as regards size, shape and configuration which are intended to be used at a particular medical facility or location. By way of explanation, as is well known in the field, many facilities use standard syringes made and sold by a particular manufacturer, such as those of the Becton Dickenson Company; however, there are syringes of many other manufacturers which are also in use at many facilities; and these are also referred to herein as standard syringes. The point is that the subject invention is sized and shaped to mate with all of the xe2x80x9ccarbon copiesxe2x80x9d of a standard luer lock type syringe stocked for use at a given facility, regardless of the manufacture of the standard syringes used at that particular facility.
As further background generally, as indicated in FIG. 1, a standard luer lock type syringe 11 is usually of plastic material; and it typically includes a barrel 1 with a nozzle 2, which are usually transparent or translucent, and define an elongate interior chamber which is in fluid communication an axial luer, passageway or long channel 3 in the syringe nozzle 2 and that terminates distally at an opening or discharge port 4; and b) an axially slidable piston 5 in the barrel with a head 6 provided with a circumferential gasket means 7. When assembled, the end face 9 of the head 6 of the piston confronts channel 3 and closes the opening or discharge port 4 of the syringe. The piston, also, includes a push rod 8 extending proximally from the head 6 and from barrel 1 for axially manipulating the head end face 9 and, consequently, the axial location of the piston head 6 in the barrel 1, either closer to or withdrawn from, the luer opening or discharge port 4. In use, the standard syringe 11, after being loaded with a drug at the pharmacy, is sealed by closing the discharge port 4 with a mating member often referred to as a luer lock or syringe cap 14 as shown in FIG. 2. To do this the cap 14 may be provided with threads 3xe2x80x3 to be threadably connected to the nozzle by a suitable mating connection means 3xe2x80x2. As shown in FIGS. 1 and 2, the threads 3xe2x80x3 are located on the interior of the nozzle 2 so as to connect to an exterior of connection means 3xe2x80x2. The connection means of the luer lock or syringe cap 14 may, alternatively, be of the type which includes the male radially extending flange portion also indicated as 3xe2x80x2 in FIG. 2. The connection may also be of the type which includes a set of circumferentially spaced ears (not shown) on the outer surface of the luer lock cap provided to threadably engage the threads on the syringe. As shown, generally, in FIG. 2 in either case, the ear type or the flange type, the radially extending portion 3xe2x80x2 of the cap 14 is sized and configured for threaded receipt in the annular, correspondingly threaded recess 3xe2x80x3 of the nozzle 2. In another form, the connection means may be merely reversed and comprise a female connection means portion on the luer lock or syringe cap for threaded connection with a male connection means portion on the nozzle 2. In some structures, the nozzle portion 2 and syringe cap 14 may each have a correspondingly tapered mating configuration for press fitting them together to join them. In this specification the term, xe2x80x9cconnection meansxe2x80x9d refers to and embraces the structure shown and or described as well as other known and usually routine means of installing a syringe cap 14 and a mated syringe 11 to close the discharge or dispensing port 4 of the syringe 11.
Turning now to the background purposes of the invention, in a hospital, for example, it is common for medical doctors to order that a patient be given an oral or an injectable dose of a drug. In the case of an injectable drug, the dose is quite often filled by a pharmacist at a location which may be regarded as a syringe filling station. It is often far from the place where the patient is to be injected. It is quite often that a syringe filling station is located on one floor of a hospital and the nurse""s station is located on another hospital floor. Indeed, at large medical facilities, a syringe filling station may resemble a factory on the hospital grounds from which drug loaded syringes are delivered to multiple nurse stations in multiple other hospital buildings. Because of the remote location of many nurses stations relative to an associated syringe filling station, a loaded syringe is very often given to another person for delivery to a nurse station for subsequent dosing of the patient by a duly qualified nurse or other medically trained person.
During the process of loading the syringe with a drug dose, the delivery of the dosed syringe and its handling in general prior to the step of actually dosing a patient by injection, there is a danger of contamination. This invention guards against that happening.
Also, especially in the case of a very expensive drug or an addictive dose, there is a danger of tampering with the loaded syringe in an effort to improperly gain premature access to the drug. A real danger is that such inappropriate action may result in a substitution of an unauthorized material in the syringe, simulating an actual prescribed or real dose. Obviously, a substitution of a substitute dose for a real dose, such as a substitution of a saline solution for a dose of morphine, may have extremely serious consequences. Thus, there is a problem of knowing if a sealed drug laden syringe has, or has not, been exposed to contamination or compromised by tampering with it. This and other problems have been further described in my earlier granted U.S. Pat. No. 4,667,837 and in other patents including in U.S. Pat. No. 5,328,474.
This invention addresses problems of making and using drug loaded syringes, some of which are described in each of the above noted patents. This is because problems remain in the field since the introduction of products according to those two patents. These include problems of easy and inexpensive assembly of the end cap assemblies in the manufacture of them, problems involved in the assembly of an end cap assembly on a drug loaded syringe at a drug filling station, and problems of maintaining sterility during storage at the manufacturing facility of the end cap assemblies, transport of them to a medical or other facility storage, and problems of storage of them at a medical facility. In summary the invention addresses problems in handling the end cap assemblies as one is made and used at different stations by different persons. In general, this invention provides an improved tamper evident end cap assembly being less expensive, safe and structured for convenient manufacture and use.
Specifically, this invention addresses outstanding problems by providing: a) an improved tamper evident end cap assembly including a captivated luer lock syringe cap for closing the discharge port in the nozzle of a loaded syringe, b) an improved sterile package with the end cap assembly encapsulated within it, for transport to, and, prior to use, for storage at a medical facility; and c) an improved combination of a drug loaded syringe and tamper evident end cap assembly for use in dosing a patient. The end cap assembly is especially adapted to mate with and be used with what is referred to herein as a standard syringe, one which.is a xe2x80x9ccarbon copyxe2x80x9d of the type used at a given medical facility where it is drug loaded and delivered to a nurse""s station for injecting a patient with the dose. Any unauthorized access to the loaded drug contents, once the syringe has been loaded and closed prior to its ultimate use, requires removal of the syringe cap by an unauthorized person, and the fact that such a removal occurred is clearly evident, if it does in fact happen.
Generally, in a first form, this invention provides an improved tamper evident end cap assembly including a captivated luer lock syringe cap for closing the discharge port on the nozzle of a drug loaded syringe. In another form, the invention provides a combination composed of a) the improved end cap assembly and b) a sterile package to keep the end cap, or a plurality of such end cap assemblies, sterile during a period of storage at a manufacturing site, during transport of it to a medical facility, and during storage there until ready for use capping a drug loaded syringe. In yet another form, the invention is of an improved tamper evident end cap assembly mounted on a drug loaded syringe for the xe2x80x9clast milexe2x80x9d delivery to a nurses""s station ready for use by dosing a patient by injection.
One specific persistent and troubling problem that has remained in the field is overcome by the disclosed structure. That problem is caused by the fact that many syringes and doses are of very low volume. With earlier tamper evident syringes a problem has been that, inadvertently, a small loaded syringe can pass axially through an end cap assembly during the step of capping a drug loaded syringe. This is especially true in the case of syringes sized for a one cubic centimeter charge of a drug. The improved structure of this invention resolves this problem. It provides a blocking means so this cannot happen.
Another problem is that syringe drug doses are often wasted. In medical practice a doctor often writes orders directing that xe2x80x9cup toxe2x80x9d a certain amount of a drug, a limit which can be safely tolerated by a patient, may be administered, if requested by the patient or circumstances justify it. This often results in drug doses being loaded into many syringes which doses are not actually administrated. These drug doses can be routinely recycled provided if there is an assurance that the drug has not been contaminated and the syringe can be opened without comprising the drug. This invention provides structure which accommodates that purpose.
After being filled with a drug at a syringe filling station, the loaded syringe is delivered to an injection location for dosing a patient. Especially while being delivered, accidental contamination is substantially prevented by this invention; and, importantly, any unauthorized tampering in an effort to access a drug in a loaded syringe with an end cap assembly according to this invention is clearly evident. Also, whatever the specifications are of a manufacturer for his particular syringe, which is standard at a given facility, the invention is adapted to be xe2x80x9ctailor madexe2x80x9d or sized to accommodate that standard syringe of that facility.
It is an overall object of this invention to provide an improved tamper evident end cap assembly which includes a captivated lure lock syringe cap for closing the discharge port or, luer opening, in the nozzel of a loaded syringe.
It is also an object to provide a sterile combination composed of: a) one or more tamper evident end cap assemblies according to this invention which includes a mating luer lock syringe cap captivated in the assembly; and b) a sterile shipping and storage package encapsulating the assembly.
It is a further object to provide a captivated luer lock syringe cap which includes a) a first one way drive means component on the luer lock or syringe cap to mate with a companionate second one way drive means component on another part of the end cap assembly, which is a mirror image of the first component, and, when the components are engaged comprise a drive means to install the cap on a syringe, and, additionally, b) a means to center the lure lock syringe cap so that it is rotatable within the end cap assembly and also is in coaxial relation and engaged with the other end cap assembly parts for driving advancement of the end cap assembly in a single axial direction along a syringe nozzle upon relative rotation of the end cap. This one way drive mechanism in the described preferred embodiment comprises what may be referred to aptly, and be conveniently denominated as, a xe2x80x9cscrew type ramp and cliff means.xe2x80x9d It is one which is capable of axially moving an axially moveable member a predetermined axial distance in one direction only. This in turn determines the force required to move the cap member not by rotating the assembly but by applying the force axially to withdraw it and gain access to a drug load in a syringe. This invention provides structure for a predetermined tightness of the cap once installed on the nozzle of a mating syringe. Thus, the invention facilitates recycling of unused drugs. This one way drive mechanism is referred to and described where appropriate as a xe2x80x9cramp and cliff meansxe2x80x9d in this specification although other equivalent structure may be provided to achieve the same result in the same way within the spirit of the invention as is well known in this art.
An overall object is to provide an end cap assembly which, once installed on a syringe, will reveal if an axial force has been applied to separate it from the syringe that is greater than occurs in normal transport and handling and is great enough to break the sealed condition of a drug loaded in the syringe possibly compromising it so that it cannot be recycled with assurances of safety.
It is a general object to disclose the forms of the invention in a best mode and in preferred embodiments; and accordingly this disclosure is addressed to those in the art in sufficient detail to make and use the invention, which may be transported and stored in a sterile condition, is composed of readily available materials and structure which is easy to use, and is otherwise well adapted for the purposes expressly and implicitly indicated herein.
It is also an object of the invention to provide a process of making the invention in its various forms and of using it.